Q&A: Five key questions about midterm elections in Congress
Will Republicans take control of the House and Senate? All 435 House seats are up for election every two years. A majority in the House is 218 seats. Republicans need a net gain of 39 seats in the Nov. 2 midterm election to get there. Polls now show the Democrats are in trouble. Why?
Why Republicans might win the House
With two months to go, political handicappers are picking Republicans to narrowly win a House majority and make big gains in the Senate, although not enough to give them control.
"The House has reached the tipping point," Cook wrote.
In the Senate, Cook predicts a Republican gain of seven to nine seats. Republicans must retain their own Senate seats and sweep nearly all of the competitive Democratic seats to win control, a difficult task in the 2010 election.